Girlfriend's restraints

I've come to the conclusion I haven't got the slightest idea on how to approach this issue kindly and calmly with my SO.

These are the premises: 1) she has no close friends. She meets her "closest" one once in a while though; 2) I have two close friends (Tom and Jerry) who have made the introduction, and we often hang out with them and other few people; 3) The GF would happily dedicate all of her time to being with me, but I feel restrained since I'd feel bad saying "you stay here while I'm hanging out with Tom and Jerry alone".

How can I make her understand she needs something to do with her life other than me and she needs to have her own interests/friends/hobbies without getting mad at her?

My good friend's wife is exactly as the OP describes. She has no friends, her wedding party consisted of girlfriends/wives of all of us who were groomsmen. She follows him everywhere and has no hobbies of her own whatsoever. Blech.

I have this problem to some extent. Mostly because my gf doesn't know that many people in London (where we live) and although she has been here for a while she was commuting long distance for a lot of that time and working in a very small company. She does have friends, but not many around, so if she is not with me she is often alone.

We both have hobbies now that do not include the other, and I have nights just with my mates and she understands that.

You have to work out if she has no friends because of circumstances and that could change, or because of something to do with her. If its the latter I'm afraid the answers above might be on the money.

If it is the former work with her so she is doing more things without you, and meeting like minded people and tell her that whilst you love spending time with her, you need to spend some time not with her either because you are having a boys night, or because you will be doing some hobby she doesn't enjoy . Hopefully between the two you should be able to manage things.